1;



x = 0:0.1:2;


function y = f(_x)
	sigma = 0.3405
	a     = sigma^6
	r_c   = 2.5
	b     = r_c^7
	c     = r_c^13
	y = (1./_x.^7) - ((2*a)./_x.^13) - ((2*a)/c) + (1/b);
endfunction

plot(x,f);

